SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a4ffdc8c59827d8bca044ac4b0aaf7acc3c4701df56de559c7e7299308e3432' 
  AND token = '57kAwujWIizbI4rPrqKqqkLLw+9KnLR1VIgGZUX86IY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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