SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ace0d50f943626058e28ad2464c2ce04bf7bfaa487e65f9328c856efe3ab4ea' 
  AND token = '4muwx8Hk1fOAshcGRXjJwddDy1VNjwBMbcmQ+O0PS1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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