SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fba33a8a62d0d54a3106e5327d66bcb0bc81cf19db966a4e98b1a3365cae9fce' 
  AND token = 'fE3Bw1osvudPzlGfHOuoc9fulGZ02pI8KfK9h8IEaFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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