SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64246d1474386c96d942adec1e835902628e69ff5d69f52c93474e49fc91b39d' 
  AND token = '+rNelYJEp3CqLyl6aYJnipPnKPw3VsieALck7cBFOzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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