SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67bec7704cfb0f5eb7143627500b206c76f00e6ce564508fe24b2a67a85c3d2c' 
  AND token = 'Bzf74ruSXvUZbPO3kRXgasxZwdtr0hQVX1MUCqQOvWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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