SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '81a01077a31815d219ce17a44f5cf4ceb623f5369f86c9429af31ede1e05bdf7' 
  AND token = 'v+SUWLBJMr8SDjKgmn7HhATQvuVwqLbywyieYqrcCVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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