SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cc1a32334d86347f39820f59a0b416136715f569f77bf6aa582a261dc9e5a74' 
  AND token = 'bLcTz/5c/pK4Sl6pqLv8KWCPKt8V5xrhV+UPiYWX2SI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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