SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acf4131ef8829baac8a6dc43ce45bea99bc6928f271aaa813f23b443753d0ba2' 
  AND token = 'zVx6Q88lLK7i6NHFQr3oPS1owYUUXbDAr6h6l50xJa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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