SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a718175da7b3529bda3022659e979c6894918289372ef10da284963bc5f880b8' 
  AND token = 'qKtMo8FwmyWMdDn1LwcaT9EU7mMoR5XM1ZlZd3iIOO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00125

JSON explain

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