SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2d68ee48f65e5fa24b38235a233a2523dfd4849163d983e0d2c7b2ff03beb0b5' 
  AND token = 'uMMsU2SWdSGlEKOqvCoSib46e8C/Yt8Y2XoM2joXe0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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