SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e2bcc5f4e135b9e314082d3c058fb37d5bbc126628c5c8e7492afbf47d64502' 
  AND token = 'Vvz1bWkgyceH61Yo7RcqwWjqCII1NnDu+xKojQyt3Wk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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