SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7e8ad8aefb4dbc345d7893d89231f807c87a70ae56cd5778619b2c243203892' 
  AND token = 'h9Vru8yMeJfb+6Mfp60rFMNnlwNvBq56MNMUwHhENO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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