SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d33ed2fda4573835b2f9d9205ae7081f94780a7d46ef637b9f553839929cb82' 
  AND token = 'ueVuBBHsoGk0gW2qDk/6wPgkRhNY2zPedulxKqpxmW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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