SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dce358ae73a1c56b0a25a153cbdf3e181b170e92e13266da3729188821f720b' 
  AND token = 'wVcZz2YopjfHYeWtnkooGcU6vRduiAPOG4+ziIu8pDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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