SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab7baeb9cf25a285d75f367a8e57e5cbb326fbede065c7a9386533167f5a4e35' 
  AND token = 'A+U3FCj0XaBp51kJMLKxWFmYAvRcI/fTXCjpn6vW4Os=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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