SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c5a7ee8cd8a1d23f473d2101483ae037b300e5f602aa802470ef37f7f49791a' 
  AND token = 'kh5wuhIEpwENBItQCgmPnSGNLJj6qwH+2I4ivJETuQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}