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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf8864d0e3f01acc6759587adfddbcf62916325ac0ac54b1468731bef8e371d6' 
  AND token = 'ImjHiMj7xezcwo+QwpPsWsJHRSiq5MFBak1MP5if4GI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}