SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed0f3f6f212e10be00181fac33560be08cec29b1a7f7425e151566df199819b0' 
  AND token = 'JiBOaX7Wp6HYiRDCQAtvSfZDwNxg8/fMNjj35BN516s=' 
  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"
    }
  }
}