SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '531a492e3af5a750dfbc3e0995addf00124aa203a173832bd53bc6c169190d9c' 
  AND token = 'jz6BNRQW43CdDY9s1PBKAaz9PaDBPMyx1SLaYFmFs3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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