SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0c1685adb24d77c38c79fc9cc5baf7ab387c2c343bc20b939bfe219d642572d' 
  AND token = 'D2EQzAkIZJOpBhBQ85QJGZO3prvLd0WuOCSqu+NVzKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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