SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b32b4fa63ff8acfeaba7dccf913ee666abdbad4cdbfb3851dc03f0cb3067e54' 
  AND token = 'kMPz/vI/ZyJykOutQK6F1XDGf1ajFTT58OpLj5fqaAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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