SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1785419eef8060c59bdc27062d5a08097852c184f6ff24219f0d81555fde3d8' 
  AND token = 'X635e91Gph/MSc1qtsOmqL39XANvTvT9gPQlz2qI7k8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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