SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd468100b60a7df01d1c88a8a1c538857642bb0f3810c169a500be8c39c341c10' 
  AND token = 'nGP3ToPxeogmw/0AQYhO8y+cOUx2cHImzSEYtRhdAAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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