SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d4c86cb0866c70283f922d65eef72089c383e81baa6678d5ef4f8f190078770' 
  AND token = 'GY+0vahwiiSxPJzR4wP4+MxSq0HOfph/PfSafK/C4Ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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