SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abe1b98a38eee6b0e0d67e4e29a0efbfca3f6eb22c70ffa03656dfbbd18322e7' 
  AND token = 'bR698h0FTpHfezmqCaJ6kS+Lg1q9hZVgNPAZ+dsJqrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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