SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a827148b0d73812753b7aa8818f70a3e04ddf92cfa12067d18708231bc57cad' 
  AND token = 'dKJIHuPkqxUA+L6g6h4QtBXjAzh+vJSLqZJfkNQm1SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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