SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efc4675d8bbdd24c63cc0efdee54fc17c39ccb54a59ef48618b99fa208a8c066' 
  AND token = 'RsaE5ibYDdzIPXifzn0jMeZzkWjZkWLr5i+Nob/tRUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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