SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc35da9b964d107fdaa8884391ee48a66836524818dbf7006e5b6d22b65f9f56' 
  AND token = 'cSc3l8W0haLloj6VahTojZPe+RsJA3tUfxuvGWo5oXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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