SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ee31e5cd8211a46eb88e773b07933fd04fa2a740b7ad09d0e02095cae6d748c' 
  AND token = '28qrnB/ogIVAlbFdaXc3hXW2R6Ru6zN0o6VL+Kq1s1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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