SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64f16a1009bace46ee825fc8e54b049b128ad6bfd617892e5548036cf14d1b9d' 
  AND token = 'r+vruEBE07HHUU59v7KJ7MOISFdA3qlalj6dYV4MoOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}