SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '647ed90af0d73a925415e6998ef33463459939750771907873dc3db2428eb3d4' 
  AND token = 'CtTHF7ynzC0ZR9kePeuN+inDvodpoWYQ7V/2cNqr2O4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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