SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e33b839a2f0d6bca9ff29259b1e3af852278898c99cc39de97f32619b0e94bbc' 
  AND token = '9fOm5yWERccHOT0Fx6VjwbFMwxieSc2bukjYQeobWYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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