SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fc16780f1a3556ce094219d71c032aedf90c3419778dfbcb342151d6b4dfe5b' 
  AND token = 'f5ru5sSTwOdzV2VGndqHkfTo1rTiD1+OAWH/6FpNKA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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