SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee18a2782120db435147c496df62eeebfe873a60b0e0a960eb1382dd91803700' 
  AND token = 'SPdAQQsih1MxCzSm3ucUdkfb96YCjo9VgnN+uWay70k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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