SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '395977bce41743c688c6691fb0cec472321dc75396c7258ee75594ccb3561034' 
  AND token = 'VtZAdEHZYUygp6xaRcYYz4YxkwLOsbkjh/aaUf7v7Qg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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