SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c527f170dc6b7e9819fbd2d195023816e2332e083391ee1093efd42c22b46738' 
  AND token = 'p7Ho0aquQuzLry9EZH2jWzIHi5Xk6RcZQQIIFpcv/0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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