SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c894197a987b4812008c1560b6f4117b3219136fd1ed90b6f32c316e877e3592' 
  AND token = 'Q9z2ZFTBz8uDhzSAUwBwWEXzf/rzR8YrJ4vzyUBjDYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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