SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c904714ca10334e55a3a6c797695ad99c8d17770b67b732f06f2484130387b38' 
  AND token = 'OeeqCtDl1OifypDvoReYf6In5r2jDK7oaTtCb4mqwe0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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