SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd6877bcaea2b22da98cbe2769d6248179ff74d7ba13eaa3d16c22c2bb57d85f5' 
  AND token = 'XRhKp6HofBGe6SNfbPL3A6bHOMKRo6xXfDyjGZXASpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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