SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'db41d1c20f7461452759562b1bda46ad5f841e2442921801d17ee877e6ff4e0a' 
  AND token = 'M2335h3K/QSzsEjLOkczDzZOoexFhKRci0RShjKmA4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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