SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b09624bad234822f8156045080d7a3fb21e359165e4f6fe813b72548bfc3cb2c' 
  AND token = 'tl09cW3xfjcU6n7v9KF+OPL2qxGCT6eZf9zyKYcjnhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}