SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08c862a42e687b36f439b6a93692c6d66acad633190255bfa525941dcf0c6d7a' 
  AND token = 'OAXrAGFCQQhLkMW2D2TMM4ckWa4ahJjcGpUA0OODOcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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