SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8f61d8d81ed65864cba5c458ce863c17de42fbd88779c18091f5c2909d59927f' 
  AND token = 'lXo+pTMOzcKFpYx62bHkAZr2lGxvCouuwJZ6WnLdZF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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