SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd4fefdc0c92f1c958ef17c4889635aec759a5c87fb187c72bff032a66f529f2' 
  AND token = 'eeA+qtNcLsjxBW8cLlwmAECl4uImwESRziUsGHP0t5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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