SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '471db62c03c9893e7170606025e5757467aab69950db2f4118d64396ceff6098' 
  AND token = 'MWd2TC5riXvBpYLliv5ejcTi17iJoa05EhGCW5Z0yX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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