SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1af0927c9c534195fff3808110c8b1f0f1f91d2765a8cc671ba85bb0e6004352' 
  AND token = '4mA9hBcauJet7GHFc/r24XwMOCZ5n1Xjr3ts/xxAucs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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