SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd8da821af2787fb878fc746762fdcb795c9135b4cd58b44c55370f1c31429bd5' 
  AND token = 'hFH+GaveJNrLBgxGwnpqrC62C5RkubTQoFRQ0CR7//k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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