SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '735b1ef2662b152cde8fbd8a6835737ef0dde3f4560708ee3d4db49c895d3924' 
  AND token = 'c7YPrSwHiCdeohVnrDzD4ZI/1clUuCp83ZjhzpxpOuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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