SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '413ca9ac7abdf83202a52b850711f6bf9a549cbce71fc8bcab7c80dcdafeaa18' 
  AND token = '/EEYinXtljp8PfP1EhTLJYzrcvC9+17lStBYchr2/Gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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