SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3d0ba138610bebe70097116718fa602138925b5645e20c3ab087bb5bd4a1f894' 
  AND token = 'fVqKrG6H7p7ze94iG57AdlKeAuBqvs+QasNGZpBN7Ys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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