SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd476cacfd3b03bb3fc94caa6184f456315f489a242067cef93299fae63d521a3' 
  AND token = 'fCpwvMSpvX+g5yJfsXQKn8cZDMRvqNdZFGeR0wpnDmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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