SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcb5053a4a6badb712263cdb06f0d6b26009f20d70509628902821b055e43581' 
  AND token = '70J8wAAI6Akg6xmOIqCM+sLe2F4jarVZuJjwVKD2vPQ=' 
  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"
    }
  }
}