SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b765f1facf3e2bf14f80620f45718021d7b6c27a8eac4d33ff610975c17286b1' 
  AND token = 'x0PBJt2ECtezog8ilXvQL+2VtSav5I62zlNiO/QpoiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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