SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0941078d874c2a5bb8e2ded7d5c9fbf85558270aa745f6bf44f27fc4c52b66b6' 
  AND token = 'zbkF7Zs/cZCV8RU2CGlSuLzSQe4+SEG0eiPoGvUKYNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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