SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cca1004b8d93a6cef6e322a7cf9397bbabbbc4f99b6ed13b7a5011ddc27fc92' 
  AND token = 'Xz65pNw5XaI2NuK4ajxzYOJoCYFU4zxjOqQWPpg89q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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