SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa2cda94aa8dfc832a1a7ecbd526da2bac896458a4f4889ce720e4fd1cbe74dd' 
  AND token = 'VSGRWfQvDR+S0Vu9x0eN2HN0OGxKh9rfmjYxjSsB4NQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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