SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7083fe5929325821fdcf395f2a8878e2325d0d3945f851ab6542ed3ad4941507' 
  AND token = 'U1xBx36Ae3Jlg1iGeXwJTiWuQXp4nQjgC0DT2pKedTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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