SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd996ff21a46e8dbcb8e09dac6212f0af956dead192a304bcefe86e3a524f7aa5' 
  AND token = 'F3hluWWz8chU5xt3OUxETWhRS3grbqe7ggpSk3GNDjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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