SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e94da66ba6ae9d68d74efafe192ee91d70ae054bba9ae1b00027fb67043eaebe' 
  AND token = 'sBxUFPyVPupOVn0ItNbpZchaSpBG+mlTIf3wk7k8Wn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}