SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36b09fa6884c46e57029b6d0195537b3c903cd53f499c271a6cb3cf4342a3ba1' 
  AND token = 'F9JyUgW2pE/mqo3DwKmlRWwm0nEITqVPsrNQ/kqzIjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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