SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1fa1663f40f8d0925a21c40bd77a6ca8e8d9daae4eb346fc7a6104013fb0994' 
  AND token = 'tj6Yv+5N346tHPuLn4yQoxShdbn7H+np2MVdGedjkis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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