SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a8697c8f7a4c49cc834bba571e78b0343da1555bd3f8c2f775cbf67b9c42936' 
  AND token = 'fMh5wozrYvSInKRwhOfAhCN9kdBy8Z+o7jf/+jyG4ZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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