SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1476d821fd8490cd5ee887901c0e4c66aaf5b6877bcb65c692ad0deb469e3faf' 
  AND token = 'kydIQG7frsrwd4buYIbdEzZTyFYPFltYHvO6xHINH6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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