SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03610747ec916824517309425cea2672a4479d8daf86eff71c96eacd616ece04' 
  AND token = 'ZYuDjV1GhgBZn9ZGpEkl2AX4KHMQ06SQ1J2PTFJSOVk=' 
  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"
    }
  }
}