SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da58df31184e17ec3ac7c21ff5b02b2d72c77dbed281b9993e82bc85ae180ba5' 
  AND token = 'qFG8KdekJD/XlMawUM6XEMV+fpGzvjHfjVc39IKqC6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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