SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10b322cee41fb610611bdf425e9205077749453b5bd7d7ecc22faffe48d8d72f' 
  AND token = 'tR0lybK+MCjinOOc7Mja0XLPdsbeAhpsrRtagv8RA1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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