SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cca8d282a0eeb94b027caa1aff19453c9c0e8c8a57fbaf0639b0625a6ed0fb9e' 
  AND token = 'gXCMpF1ooqoNlL7slWvrSr9clfCrXUqo8e199+emxW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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