SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '41b589a9ff3b3d0bc009fb60089df51e50c25f03555482547ad045d4f861f78a' 
  AND token = 'oVtHkt6Mwa5vwBFvm3ISUinhQgUKe6Zru2P6mpmFwgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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