SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8930fe98def22a46a41408c68d4aa854375675b9718c2339413f106a483a4ff' 
  AND token = 'EwE7lMz9+JnHVj8Ghb6Fj0egTr9Uk1ldltBcL7C3P1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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