SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67ec4e8724f593d57de101111db4b764efeb97c12f6edcac65f5027eac4cc8c6' 
  AND token = 'kywopGny0qorH8Ulu1KViz3JVfwhhhjEo+BYo9/dJ74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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