SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '711ce625336910a7ab8ea924ecd51e80cd37131646eb85ef9a0dba8e0ec3eb2a' 
  AND token = '9DwNqctGw6TyIdEFz+aYbT4xXfe1kLoVscjDdmOA4B4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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