SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b61514db1940b15f9b0aa97f136677b750146d977185004eccd59cd9b8ee75e8' 
  AND token = 'tHMMugJXDcNkd9MgRYV4sPJx4J7HYuu8QrwU6j8tVqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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