SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5fef1382b0941e8fff5e8190b6d28f3b0ced181bc62a643696ec1b7336acd05' 
  AND token = 'oAhnJMjfW7KJwF0uKftly0Clil/xcYuEmsQr28zf6Ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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