SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '12b36fc7738f3bcd0681527b54e82bcae4a3ab2488c44707c47c48217e326f14' 
  AND token = 'HzjfW4XMy/7gZODIRZNIVUO/rqq5wCB9IoL4zF1ZcgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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