SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3a4af40707af1417fe4f401077307607cb77b0be9abe18a579938d0a761dcd8' 
  AND token = 'aXSxHotooF4hkFNfwveGAcT56nR8jLBvXMxjmlZfB/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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