SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feb567b7632861689893910f664f69c723ee0e62190b52299436c13451a4b20e' 
  AND token = 'sJ12cok25GeZbRYfYjrIHeiP79v/JxyoLuxbmuNZQVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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