SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e92b2f2f4432f72fce4b281b4341282ea78d058df45098ed8348bb6bfe0f8f5f' 
  AND token = 'l7nvQBdnV0CJiPIiKCDsZKLw34GQr24LEGQilVHZFRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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