SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70b96c1826a9d42cbb56e14954a7ca93cf6a893d58e7df2ebda69ffe6eb2c8e9' 
  AND token = '8rUaF8WGznD3UJv+GtZh+5fRjSohwzUWvZWr9yGABiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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