SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12e7ab6dd68a769e9aa87a7679cb6c042399eb0f07d1a24b748a8fc095a1e7e1' 
  AND token = 'zpw2l1dNbRr+PRAuMumkGxmg3vgioFqQvDqCso5UOX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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