SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bd5183818c28a87d161a1d7910d8e7d61b78d600f227050bd4fb6a2be2c4553' 
  AND token = 'Fo8yuPfSWf9LxO30XoP8DVHmvxEdWxPpqe7pN9tj+eY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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