SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8946126bcc9cefe2cb9c1a2637a190106597a1f166be6ea21ac888548e80922d' 
  AND token = 'vN6lnU6cq3vzWBOQNnYhWJhuU2n6JQutu24iN0tCVYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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