SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f666cefd85dc022acb5bf9121a80271c86587f3ef1685cc046b9b25dae92b61' 
  AND token = '/b7LcbxJjN9qDoU+HzoV1A2IjKHHkzMacu+ya0pVe0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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