SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca94d4216853f56108207b4b7ea8160add133ab147a3c08cc59f28c7cee940c8' 
  AND token = 'e+PQs8b6KhKUhp4WfRNMJsY3meajkFOJA+QGyrJe+2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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