SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a77679049656b86dccb7d77f0dab22fc8a3d36e2cc8d50c2c1a7f351d13d1262' 
  AND token = 'BDeBN3Gxuui0eQRE3nJMZmgBfm95BCg+A9ftbcqrQlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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