SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e017dba42ea7b16466ff343af73d0505788f7572c39aaffb74eaeac4923097e4' 
  AND token = 'i6H7ykUHQHt6uMeoYhzfqX6oCRiBeNFFlhctuQX5iLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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