SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4327b6910ca89dacf5f96d4d0b5166c8e948a8da4c7f2ac0fa20b70d86748f03' 
  AND token = 'dL1cRrJAOaZ6vpM5WLt393rCWSYqqzrcSyBCyEhRikM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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