SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40f43b47a24292f375dfa087792dacb03f978225930342bf6a53a471e2233615' 
  AND token = 'cTEJRZGBQ5xY5nqSe2VwsZYcLlwBNQEosJrLlqN0a88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}