SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16ee505e18390e5002efe7894a002fec54dd1fc008b91b86372e455b428ac6b9' 
  AND token = 'r7TAHXMMsjzs1MoDUbr61ZU2kRq9aPtpibjoswKI/zs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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