SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dafcb9da91e6374b8aa13c51f011357756badc39c9949e802368fb51202e5a4a' 
  AND token = 'oeleQfNxRT62m5FFq8tsNy3vWBXJhjCW9LIcwqtykRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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