SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfb1c4eca259f9683ed9509031df79c04418928fdcb7acc7b2a3b0f79374b160' 
  AND token = 'nNO+eEPp11hVwFYUy2K+dVUf1mtv0TJMtILeA5ELhOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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