SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3a269a4830227eb4d8f8e978ba3878404340ca25760b9905d3eb96700034c73' 
  AND token = 'XvkArHMvrAWZSOGmH/ub5Bnj2YSgZMNvsjAihX/wyXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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