SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd54798a398db70c0cad59b28eb4b9351577ae1aa3e40ed525e0af7607e2f75d1' 
  AND token = 'l4d0InfUmtgDwYqLI6trSxAayZmdjJtiSFs3Lor8Jrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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