SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ebe4cf82233f5fffb2313d43b748a4d2eea1fc1563394313eceb4850bad7b387' 
  AND token = 'CccDuvOIvUQHFcfQ7IDLCBBl9dfdeeEryr9CnQ8gWBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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