SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ff6c3445841039eda79f62d3ac1c4842170b422d43930273225ea2369bb80bb' 
  AND token = 'rGC/NkMmiMQDVXrlR2qL6BmwGzdz5P6zrpZAmkwlMTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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