SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b5ce5fb1a9a86c2947e110266953b3459918fb26ab900f60757b4239e1181c34' 
  AND token = 'HQD/5XFUwvr83O5veoG4wbqi5ksGrbO7vRnJzFCw/IE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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