SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f66d1b5d2d538619a2481637f5f59a609b92609a99f350e61cc78b8ec78bee26' 
  AND token = 'K3ybhCeoh9To6Kd9Lq0xLSn9ohogbtwl8s6GFl4y6M8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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