SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fda27c8f75eb9f125ff8e68d3f2073b623d507c5bb18e56fc10556c35543230' 
  AND token = 'YGNCc87wi5InDXwB+DgzASEDK5WhVm/wBh3/LInVnFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}